This invention relates to a device for accomplishing, on a television screen, a special video effect such that a present scene is gradually shifted into another scene. The special effect like this will hereinafter be called gradual scene shifts in the instant specification for brevity of description.
Formerly, gradual scene shifts were optically carried out by the use of a film. A special video effect device has recently been proposed, wherein the gradual scene shifts are electronically carried out with the help of a random access memory for storing one of the scenes and a mixing circuit for mixing the stored scene with another scene. The electronical scene shifts are useful as compared with the optical scene shifts in view of rapidity of reproduction. As will later be described with reference to several figures of the accompanying drawing, the device is, however, inconvenient because the gradual scene shift is achieved by moving only one of the scenes. It is possible to move both scenes if a special effect device is provided with another random access memory at the cost of a much increased expense. Therefore, the device is inevitably expensive.